1. Field of the Invention
The present invention relates to handover techniques in the field of wireless communication, and more particularly, to a system and method for processing handover of a mobile communication device between femtocell base stations.
2. Description of Related Art
In the development of network communications, network coverage has long been a focus of concern for communication service providers and an important factor considered by users when choosing communication service providers. Currently, the coverage of wide area networks is quite stable. For example, the coverage of macrocell base stations can reach sparsely populated regions and fast moving users and even reach remote villages.
But in buildings of densely populated cities, the macrocell coverage is quite poor. Therefore, femtocell base stations are developed to extend the coverage of mobile networks so as to overcome the above-described drawback of poor indoor coverage.
As known in the prior art, handover of a mobile communication terminal such as a mobile phone between different macrocell base stations is a process of signal comparison. That is, when the mobile communication terminal detects multiple macrocell base stations in its vicinity, it tends to select the one with highest signal strength. Since the macrocell base stations are connected together through optical fibers, it leads to a high message exchange rate between the macrocell base stations and accordingly leads to a synchronous signal comparison between the macrocell base stations, thereby ensuring that the mobile communication terminal is handed over to the macrocell base station with best communication quality.
In contrary, since femtocell base stations are connected through network cables with a significantly lower signal transmission rate compared with that of the optical fibers, a synchronous signal comparison cannot be achieved between the femtocell base stations. A femtocell base station performing a signal strength comparison cannot timely capture a signal reference value (signal strength) from another femtocell base station, which leads to an uncertainty in the comparison result such that the mobile communication terminal may be handed over to a femtocell base station with poor signal strength.